Abstract: A generalization of the density functional based tight- binding method (DFTB) for the use with range-separated exchange- correlation functionals is presented [1]. It is based on the generalized Kohn-Sham (GKS) formalism and employs the density matrix as basic variable in the expansion of the energy functional, in contrast to the traditional DFTB scheme. We will discuss details of a numerically efficient implementation and present first results on quasiparticle gaps in organic molecules and the extension of bipolaronic defects in polythiophenes.